There exists several methods for preparing alkoxysilanes and silicone resins. Conventionally, separate synthesis processes are carried out for each product.
For example, trimethylethoxysilane may be used as a hydrophobic treating agent for silica in defoamers, as a treatment for the dry powders in fire extinguishers to impart free flowing properties and other similar uses. Trimethylethoxysilane may also be used as an end blocker in silicone fluid synthesis and as a reactive silane in contact lens manufacturing processes. Conventionally, trimethylethoxysilane is made by reacting trimethylchlorosilane with ethanol in the presence of an acid receptor, such as pyridine. Yields by this method are low and accordingly, the product is very expensive.
Alternatively, chlorosilane may be reacted with alcohol to derive an alkoxysilane and hydrogen chloride gas as a byproduct.
Methyl silicone resin is a valuable resin which is useful as a hard coating for plastics and acrylics. Common methods for making the silicone resin include the reaction of an alkoxysilane and water resulting in hydrolysis and condensation. Some unreacted hydroxyl groups always remain and are highly reactive. Because of the reactivity of the free hydroxl groups of the resins, shelf stability of the resin is poor. If catalyst is added, the resin will cure in the container. Amines cannot be added to this system without the result of curing prematurely.
The present invention provides an efficient means for producing both a specific alkoxysilane and a silicone resin having commercial significance. The method combines readily available and inexpensive alkoxysilanes to generate alkoxysilanes and silicone resins which otherwise would be much more difficult to obtain and expensive to produce. The method can be used to make novel products as well as products previously available yet prohibitively expensive to utilize commercially.
The resins produced are free of reactive hydroxy groups. Therefore, amine groups can be incorporated into the molecules without premature gelling of the resin in the container. Shelf stability of the resin product is very good.